Stamping machine



March 18,1952 A. BAUER STAMPING MACHINE Filed Aug. 24, 1950 FIG. 2

FIG. 1

M 6 w Z n Al/rwl 4 w 2 W" A'H-urmey Patented Mar. 18, 1952 ApplicationAugiist 24, 1950,;Serial No, 181,200

In Switzerland December 12, 1-949 1 claim.

This invention relates to improvements in stamping machines and "is particularly adapted, among other uses, to the stamping of characters 'for business machines, such as typewriters and the like.

Among its principal features, a'machine according 'to the invention comprises two circular parts. disposed tangentially and inside each other, and rolling on each other, one of said parts carrying or forming a stamping matrix, and the other part carrying or forming the surface or surfaces to be stamped; the machine further comprises means for causing the synchronized rotation of the matricing part and of the part to be stamped, as well as means for pressing the circularmatri'x on the circular surface or surfaces to be stamped.

The foregoing and other features of the invention will appear from the following description and attached drawing, which are given by way of illustration only.

By reference to the drawing:

Figure 1 is-a sectional elevation of a device according to the invention;

Figure 2 is 'a plane view of a detail of said device;

Figure 3 is a diagram illustrating the operating principle of said device.

The device illustrated in the drawing comprises a block 'I supporting a motor 2 and astation'ary'frame 3. A rotating frame 4 is mounted within said stationary frame 3 on bearings 5, B

and 1 engaging stationary frame 3 and rotary frame 4. I

Atransmissio'n device, such as pulley 8, is attached to rotating frame 4 and forms, by means of belts 9, a transmission for the rotation of motor 2 to rotating frame 4. Three shafts, respectively numbered H], II and I2 are mounted rotatably on and inside rotating frame 4 by means of bearings l3, l4 and I5, respectively. Of said three shafts, H), H and I2, shaft l alone is fconcentric and coaxial with rotating frame 4.

The blank forms for typewriters or other machines type or characters are numbered l6 and are disposed on an annular support l1 and radially thereto; support I! fits within a recessed seat l8 of a frame l9 mounted on stationary frame 3. The heads of blank forms I 6, which are to be stamped, form as a whole a circular surface concentric with the axis of rotation of frame 4. A roller 20, bearing on its peripheral surface several matrices 2|, is mounted at one end of shaft H, said peripheral surface being tangent with the circular surface formed by the (c1. rob-4015i heads of forms l6. Shaft It is supportedat or near its other end by a bearing [4, and terminates at said other end by a gear 23, which engages a fixed gear 22 attached to stationary frame 3, gear 23 meshing with the inner periphery of gear 22.

As a result of the combination of elements so far described, when frame 4 rotates, roller '20 rotates simultaneously around its axis (as shown by arrow 24, Figure 2) and around the axis of rotating frame 4 (as shown by arrow 25, Figure 2). g I

The end of shaft I 0 within the rotary frame 4 carries a gear28, while its other and carries a pulley 29 rotated by motor 2 by means of belts 30.

Shaft l2 bears at one of its ends a gear 2! which engages gear 28, and at its other end, and substantially at the level of roller 20, a

slightly excentric wheel 26, the object of which is to press roller 20 against type blanks IS. The pression so produced causes, during the stamping operation, a slight displacement of roller 20 as a result of the playof's'haft l l due to the fact that said shaft is supported only at one of its ends, that opposite the end bearing roller 20.

The gear ratio between gears or pinions 27. and 28 is such that shaft I2 revolves very slowly, so that the pressure caused by exce'ntric wheel 26 on roller 20 increases progressively during each complete revolution of roller 20 over all the forms I6.

The apparatus described hereinabove permits stamping accurately'and precisely the blanks IE; it may be used for stamping any time the operation must be effected on a -circular surface,

and is therefore not limited to the stamping of characters for businessmachines or typewriters.

Inan alternative form, the relative position of roller 20 and form-holder I! may be reversed from that illustrated in Figure 1, that is to say the form-holder may be disposed inside the matricing roller. Moreover, the invention comprises devices in which the outer one of these two parts rotates around its center, while the inner part rotates merely around its own center.

During the operation, the circular blank holder I1 is slightly squashed and its diameter is slightly changed. Therefore, should the matrix 20 be outside the form-holder l1, said matrix would not simply roll accurately over the formholder, but would also slip slightly over the latter during its revolutions. According to the invention as shown in Figures 1 and 2, the stamping roller or matrix is located inside the circle formed by the heads of blanks l6, and in this specific illustration, its diameter is one-half that of the latter circle. This arrangement avoids any slippage of one part relative to the other, irrespective of the extent to which said parts are squashed by the operation. The principle of this arrangement is illustrated in Figure 3.

In Figure 3, circle 11 represents the circle formed by the heads of the blanks to be stamped, such as IS in Figure 1; circle 1) represents a stamping matrix, such as 29 in Figure l, tangent at O with circle a, but outside the latter, while circle 0 represents a similar matrix located inside circle a. The centers of circles a, b, and c are located on a common line Z. The diameter of circles b and c is one-half that of circle a.

The stamping process by means of matrix 0 can be analyzed as follows: let a point A be selected on circle a and the radius d of circle a through point A be traced, said radius intersecting circle c at point C; let it be assumed that point C is still on circle a, which assumes an important squashing equal to CA; in practice this squashing is far from being as important as shown in Figure 3, in which relative proportions have been enlarged for a better understanding. According to the foregoing/matrix 0 begins to contact blank-heads a at point C. If the matrix is to roll, without slipping, over part a, up to point 0, at the same time as the concomitant squashing occurs, then are OA must equal are 00. Let the following elements be designated in the following manner:

The radius of circle 0 by the symbol e;

The angle formed by radius d and line I by the The following relations are obtained:

OA=ad (2) 00 58 In order that OA=OC', it is necessary that ad=fl6 Formula 3 gives d c 2 since, under the assumptions made with respect to the location of point C, etc., d, radius of circle .a is double the radius 6 of circle 0. Therefore,

in order that OA=OC, it is necessary that and extended to intersection D with matrix b;

all)

let the intersection of f with circle 0 be designated as E; let it be assumed that point D belongs to part a (as was done previously with respect to point C). Now, in order that the squashing of D onto B be effected by rolling of the matrix D withoutslippage, arc OD must be equal to are OB. A demonstration similar to the preceding shows that OB=OE; but it is apparent and can be demonstrated that OE is not equal to OD and therefore that 0D is not equal to CB. Therefore in that case, point D will reach point B as a result of both a revolution and a slipping movement, and the latter is obviously detrimental to the accuracy and sharpness of the stamping.

It is within the purview of the invention to utilize machines in which the ratio of the radii of the inner piece and the outer piece is not onehalf, but in which this ratio may be one-third, one-fourth, or any other selected value. In those cases, an apparatus in which the matrix and the circle formed by the blank-heads are inside each other will be smaller and occupy less space than a machine in which these parts are outside each other.

I claim as my invention:

A stamping machine which comprises: an outer circular stationary frame having a central axis; an inner rotary circular frame coaxial with said stationary frame; an annular characters support at one end of said stationary'frame; a circular stationary gear attached to the inner face of said stationary frame at a distance from 'said annular support; a first rotary shaft par allel with said central axis and excentered with respect thereof, said first shaft being rotatably and yieldingly supported by and within said rotary frame, and having at one end a matrix bearing roller tangent with said annular support, and at its other end a first gear engaging said stationary gear; a second rotary shaft parallel with said central axis and excentered with respect thereof, and rotatably supported by and within said rotary frame, said second shaft having at one end an excentered wheel within said annular support and tangent with. said roller, and at its other end a second gear; a third rotary shaft rotatably supported by said rotary frame, coaxial with said central axis, and having 1 at one end within said rotary frame a third gear meshing with said second gear, and having its other end extending beyond said stationary frame; and means to impart rotation to's'ai rotary frame and said third shaft. g l

, ALFRED BAUER.

REFERENCES CKTED The following references are of record :in the jNumber Name 434,540 Ecaubert Aug. 19, 1890 990,912 Schwahn May 2, 1911 

